In prior U.S. Pat. Nos. 4,408,701; 4,328,909, 4,555,371, 4,363,424, 4,523,697, 4,520,950, 4,570,830, 4,564,483 and 4,664,292 various aspects of an in-home drink dispenser are described. The dispensers disclosed therein have been found to work quite well, particularly the embodiments utilizing gravity feed of the concentrate, for example, the system disclosed in U.S. Pat. No. 4,570,830. There are, however, certain problems with these previous systems. One problem is in maintaining the desired degree of carbonation in the drink. Another problem encountered is the spitting or sputtering which occurs upon the initial opening of the dispense valve due to a build up of pressure.
The previously disclosed system included passages for the diluent in a manifold. There was an area between the connection to a carbonator tank and the dispensing valve where diluent was maintained when the carbonator was disconnected from the system. If the diluent, e.g., carbonated water, was left in these passages for a long period of time, it would, of course, warm up and lose its pressurization and its carbonation when dispensed. Although this is not a major problem, it was felt desirable to avoid this.
In an in-home drink dispenser, it is, of course, important to know how much carbonated water is left and also how much carbon dioxide is left. Knowing when one is about to run out of carbon dioxide is of great importance, particularly where a cylinder is not immediately on hand. The carbonator can be refilled with water and ice, however, if one runs out of carbon dioxide, at a time when the supplier is not open for business, it may be necessary to wait, possibly over a weekend, to get a new cylinder. Thus, the need for an indication of this level is particularly important. Furthermore, in regard to the carbon dioxide cylinders, since the cylinders are being handled by people not used to such, there is a need to take measures to protect the cylinders and to provide for ease of use and insertion and removal from the drink dispenser.